R.sup.2 is hydrogen, C.sub.1 -C.sub.14 alkyl, C.sub.1 -C.sub.3 chloroalkyl, C.sub.1 -C.sub.3 fluoroalkyl, C.sub.5 -C.sub.7 cycloalkyl, C.sub.1 -C.sub.4 alkoxy, phenyl, or phenyl mono- or disubstituted with C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.4 alkoxy, hydroxy, nitro, chloro, fluoro, or tri(chloro or fluoro)methyl;
R.sup.3 is C.sub.1 -C.sub.4 alkyl, C.sub.5 -C.sub.7 cycloalkyl, or benzyl; or
a pharmaceutically-acceptable salt thereof; are nonsteriodal antiestrogens and antiandrogens. These compounds are useful in the treatment of mammary and prostatic tumors, and in the treatment of mammary and prostatic fibrocystic disease. The formula I compounds are described in U.S. Pat. No. 4,418,068 (issued Nov. 29, 1983). This patent described the preparation of these compounds, as well as their use for antiestrogen and antiandrogen therapy. The preparation of pharmaceutical compositions for antiestrogenic and antiandrogenic therapy was also described.
Raloxifene, which is 6-hydroxy-2-(4-hydroxyphenyl)-3-[4-(2-piperidinoethoxy)benzoyl]benzo[b]thi ophene, is a particulary useful compound from this series of benzothiophenes. Raloxifene competitively inhibits estrogen action in a number of in vitro and in vivo models. Black, Jones, and Falcone, Life Sci., 32, 1031-1036 (1983); Knecht, Tsai-Morris, and Catt, Endocrinology, 116, 1771-1777 (1985); and Simard and Labrie, Mol. Cell. Endocrinology, 39, 141-144 (1985). This compound also displays some estrogen-like actions in addition to its estrogen-antagonistic effects. Ortmann, Emons, Knuppen, and Catt, Endocrinology, 123, 962-968 (1988). A recent report suggests that raloxifene is useful in the treatment of osteoporosis in postmenopausal women. Turner, Sato, and Bryant, Journal of Clinical Investigation (In Press).
The formula I compounds may be administered as pharmaceutically-acceptable salts. A particularly useful pharmaceutically-acceptable salt of raloxifene is the hydrochloride salt. This salt form is easily prepared by the addition of hydrogen chloride to a solution of raloxifene in an organic solvent, such as tetrahydrofuran or methanol. Aqueous solubility of raloxifene hydrochloride, however, is far below what would be expected for an organic hydrochloride salt containing two phenolic hydroxyl groups. This poor solubility has somewhat limited the bioavailability of this preferred salt form. Another significant barrier to optimum and consistent absorption of raloxifene hydrochloride is its hydrophobicity.